Method for producing a fluorine-containing compound

ABSTRACT

The present invention provides a method for obtaining a compound useful as a raw material for various fluororesins in high yield by a short process by using a starting material which is inexpensive and readily available.

TECHNICAL FIELD

The present invention relates to a method for producing an industriallyuseful fluorine-containing compound, particularly to a process forproducing (a diacyl fluoride having —COF groups at both terminals, and acompound having fluorinated vinyl groups at both terminals. Further, thepresent invention provides a novel intermediate useful for producing adiacyl fluoride which is useful as a precursor for a raw material offluororesins.

BACKGROUND ART

A fluorine-containing monomer such as a perfluoro(alkyl vinyl ether) isuseful as a raw material monomer for heat resistant and chemicalresistant fluororesins. For example, a perfluoro(alkyl vinyl ether)having carboxyl groups in its molecule, is useful as a raw materialmonomer for ion exchange membranes and can be produced via a diacylfluoride (J. Fluorine Chem., 94, 65-68 (1999)).

Further, as a method for fluorinating all of C—H portions in ahydrocarbon compound to C—F, a method wherein fluorination is carriedout by means of fluorine (elemental fluorine), or a method whereinfluorination is carried out by using, as a fluorine atom source, aproduct formed by electrolysis of hydrogen fluoride in an electrolyzer(i.e. a method so-called an electrochemical fluorination reaction), isknown. Further, a gas phase method and a liquid phase method are knownfor the reaction employing fluorine.

Further, a method is also known wherein a perfluorinated ester compoundhaving at least 16 carbon atoms, is pyrolyzed to obtain an acid fluoridecompound. It is disclosed that an acid fluoride compound can be producedby a method wherein a hydrocarbon type ester compound having acorresponding carbon skeleton, is fluorinated by a liquid phase methodemploying fluorine gas (J. Am. Chem. Soc., 120, 7117 (1998)).

Further, as a common method for producing a diacyl fluoride, thefollowing method employing iodine and fuming sulfuric acid, is known.CF₂═CF₂+I₂→ICF₂CF₂IICF₂CF₂I+CF₂═CF₂→ICF₂CF₂CF₂CF₂IICF₂CF₂CF₂CF₂I+SO₃→FCOCF₂CF₂COF

Further, a method is also disclosed wherein a diol diacetate containingno fluorine is used as the starting material, this material is directlyfluorinated in 1,1,2-trichloro-1,2,2-trifluoroethane (hereinafterreferred to as R-113) to produce a perfluorodiol diacetate, and thenthis is subjected to a dissociation reaction of the ester bond inpyridine to obtain a perfluorodiacyl compound and CF₃COF (U.S. Pat. No.5,466,877).

Further, a method is also proposed wherein CF₂═CF— of a compound havingCF₂═CF— at one terminal and —COF at the other terminal, is halogenatedwith e.g. chlorine gas, and then, the other terminal is pyrolyzed toCF₂═CF—, and further by dehalogenation, CF₂═CF— is regenerated, toproduce a compound having fluorinated vinyl groups at both terminals(JP-A-1-143843).

Further, a method for producing CF₂═CFOCF₂CF₂CF═CF₂ by pyrolysis of apotassium salt of a dicarboxylic acid such as KOCO(CF₂)₄OCF(CF₃)CO₂K, isreported (J. Org. Chem., 34, 1841 (1969)).

The electrochemical fluorination reaction has had a drawback such thatan isomerization reaction, cleavage and re-bonding reactions of C—Cbonds, etc. are likely to take place, whereby the intended compound cannot be obtained in high purity. Further, there has been a problem thatwhen reacted with fluorine in a gas phase, C—C single bonds undergocleavage, whereby various types of by-products tend to be formed.

It is reported that the method of carrying out the reaction withfluorine in a liquid phase, is a method for solving the problems of thegas phase method (U.S. Pat. No. 5,093,432). As a solvent for thereaction to be used for this liquid phase method, a solvent capable ofdissolving fluorine, is usually employed. However, a nonfluorinated typehydrocarbon compound or a hydrocarbon compound having a small fluorinecontent is hardly soluble in a solvent, whereby a problem has beenobserved such that the reaction will not proceed smoothly. Further, in aconventional liquid phase method, the reaction is carried out at a verylow concentration, whereby there has been a problem that the productionefficiency is poor, the reaction will be in a suspension system which isdisadvantageous to the reaction. Further, there has been a problem thatwhen the liquid phase method is applied to a low molecular weighthydrocarbon compound, the yield by the reaction tends to be very low.

Further, the conventional method for producing a diacyl fluoride has hada problem that the price of the raw material is high, and the method iseconomically disadvantageous. Further, iodine, fuming sulfuric acid,etc. are used, whereby there has been a problem that the apparatus islikely to be corroded, or handling of the reagent for the reaction tendsto be difficult.

Further, in a case where a diol diacetate having no fluorine, isfluorinated in a liquid phase, there has been a problem that adecomposition reaction of the raw material substrate is observed.Further, the method of employing R-113 has a problem that such a methodmay not be used in future.

Further, the conventional method for producing a compound havingfluorinated vinyl groups at both terminals has had a drawback such thattwo step reactions are required to form two fluorinated vinyl groups,and the substrate for the pyrolysis is hardly available and expensive.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to solve the problems of theconventional methods and to provide a method whereby afluorine-containing compound can be produced from an inexpensivereadily-available raw material compound in a short process.

Namely, the present invention provides a method for producing afluorine-containing compound, which comprises reacting the followingcompound (1) with the following compound (2) to produce the followingcompound (3) (provided that the compound (3) is a compound having afluorine content of at least 30 mass % and has a hydrogen atom or anunsaturated bond which can be fluorinated), fluorinating the compound(3) in a liquid phase to produce the following compound (4), followed bya cleavage reaction of E^(F) of the compound (4) to obtain a compound(5) and/or a compound (6):E¹-R^(A)-E¹  (1)E²-R^(B)  (2)R^(B)-E-R^(A)-E-R^(B)  (3)R^(BF)-E^(F)-R^(AF)-E^(F)-R^(BF)  (4)E^(F1)-R^(AF)-E^(F1)  (5)R^(BF)-E^(F2)  (6)wherein

R^(A), R^(B): R^(A) is a fluorine-containing bivalent organic groupwhich is the same as R^(AF), or a bivalent organic group which will beconverted to R^(AF) by a fluorination reaction, and R^(B) is amonovalent organic group which is the same as R^(BF), or a monovalentorganic group which will be converted to R^(BF) by a fluorinationreaction,

R^(AF), R^(BF): R^(AF) is a fluorine-containing bivalent organic groupwhich is the same as or different from R^(A), and when different, it isa group having R^(A) fluorinated, and R^(BF) is a fluorine-containingmonovalent organic group which is the same as or different from R^(B),and when different, it is a group having R^(B) fluorinated,

E¹, E²: reactive groups which will react to each other to form abivalent connecting group (E),

E: a bivalent connecting group formed by the reaction of E¹ and E²,

-   -   E^(F): a group which is the same as E, or a group having E        fluorinated, provided that at least one selected from R^(AF),        R^(BF) and E^(F), is a group formed by a fluorination reaction,        and

E^(F1), EF²: each independently is a group formed by cleavage of E^(F).

Further, the present invention provides the method wherein the compound(5) is the following compound (5-2), and such a compound is pyrolyzed toproduce the following compound (7-2):FCO-Q^(F1)-R^(AF)-Q^(F2)-COF  (5-2)CF₂═CF—R^(AF)—CF═CF₂  (7-2)wherein

R^(AF): as defined above, and

Q^(F1), Q^(F2): each represents —CF(CF₃)— or —CF₂—CF₂—.

Further, the present invention provides a compound selected from thecompounds of the following formulae:CF₃CF₂COO(CH₂)₄OCOCF₂CF₃  (3-12),CF₃CF₂COOCH₂CH (CH₃)O(CH₂)₄OCOCF₂CF₃  (3-13),CF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃  (3-14),CF₃CF₂CF₂OCF(CF₃)COOCH₂CH(CH₃)O(CH₂)₅OCOCF(CF₃)—OCF₂CF₂CF_(CF)₃  (3-15),CF₃CF₂COO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCOCF₂CF₃  (3-16),CF₃CF₂COOCF₂CF₂CF₂CF₂OCOCF₂CF₃  (4-12),CF₃CF₂COOCF₂CF(CF₃)OCF₂CF₂CF₂CF₂OCOCF₂CF₃  (4-13),CF₃CF₂COOCF₂CF₂OCF₂CF₂OCOCF₂CF₃  (4-14),CF₃CF₂CF₂OCF(CF₃)COOCF₂CF(CF₃)OCF₂(CF₂)₃CF₂OCOCF(CF₃)OCF₂CF₂CF₃  (4-15),CF₃CF₂COO(CF₂)₂O(CF₂)₂OCF(CF₃)CF₂OCOCF₂CF₃  (4-16),FCOCF₂O(CF₂)₂OCF(CF₃)COF  (5-16).

BEST MODE FOR CARRYING OUT THE INVENTION

In this specification, an organic group is a group wherein carbon atomsare essential, and it may be a saturated group or an unsaturated group.As the organic group which will be fluorinated, an atom which can besubstituted by a fluorine atom (such as a hydrogen atom bonded to acarbon atom) or an atomic group which can be substituted by fluorineatoms (for example, —CF═ CF— being a carbon-carbon unsaturated doublebond, will be converted to CF₂CF₂— by a fluorination reaction, and —C≡C—being a carbon-carbon unsaturated triple bond will be converted toCF₂CF₂— or —CF═CF— by a fluorination reaction) may, for example, bementioned. The organic group in the present invention is preferably onehaving a carbon number of from 1 to 20, particularly preferably onehaving a carbon number of from 1 to 10, from the viewpoint of thesolubility in the liquid phase which is used for the fluorinationreaction.

As the monovalent organic group, a monovalent hydrocarbon group, ahetero atom-containing monovalent hydrocarbon group, a halogenatedmonovalent hydrocarbon group, or a halogenated (hetero atom-containingmonovalent hydrocarbon) group, is preferred. As the bivalent organicgroup, a bivalent hydrocarbon group, a hetero atom-containing bivalenthydrocarbon group, a halogenated bivalent hydrocarbon group, or ahalogenated (hetero atom-containing bivalent hydrocarbon) group, ispreferred.

The hydrocarbon group is a group comprising carbon atoms and hydrogenatoms, and the hydrocarbon group is preferably one having a carbonnumber of from 1 to 20, particularly preferably from 1 to 10, from theviewpoint of e.g. the solubility in a liquid phase at the time of thefluorination reaction. In the hydrocarbon group, a single bond or anunsaturated bond may be present as a carbon-carbon bond. The hydrocarbongroup may be an aliphatic hydrocarbon group or an aromatic hydrocarbongroup. An aliphatic hydrocarbon group is preferred. The structure of thealiphatic hydrocarbon group may be a linear structure, a branchedstructure, a cyclic structure or a structure having a ring structurepartially. As the organic group, a saturated group wherein carbon-carbonbonds are made only of single bonds, is preferred.

In a case where the hydrocarbon group is a monovalent saturatedhydrocarbon group, it may, for example, be an alkyl group, a cycloalkylgroup or a monovalent saturated hydrocarbon group having a cyclicportion (such as a cycloalkyl group, a cycloalkylalkyl group or abicycloalkyl group, a group having an alicyclic spiro structure, or agroup having such a group as a partial structure), and an alkyl group ispreferred. In a case where an aliphatic hydrocarbon group is anunsaturated group, a monovalent aromatic hydrocarbon group is preferred,and a phenyl group, an aryl group or such a group having a substituent,is particularly preferred.

In a case where the aliphatic hydrocarbon group is a bivalent saturatedhydrocarbon group, it may be a group having one of hydrogen atoms of theabove-mentioned monovalent saturated hydrocarbon group converted to aconnecting bond, and it may, for example, be an alkylene group, acycloalkylene group or a bivalent saturated hydrocarbon group having acyclic portion (such as a bivalent saturated hydrocarbon group having,as a partial structure, a group selected from a cycloalkyl group, abicycloalkyl group and a monovalent group having an alicyclic spirostructure, a cycloalkylene group, a bicycloalkylene group, or a bivalentsaturated hydrocarbon group having, as a partial structure, acycloalkylene group or a bicycloalkylene group), and an alkylene groupis preferred. As the bivalent aromatic hydrocarbon group, a phenylenegroup, an arylene group or such a group having a substituent, ispreferred.

In this specification, the halogen atom is a fluorine atom, a chlorineatom, a bromine atom or an iodine atom, and preferred is a fluorineatom, a chlorine atom or a bromine atom. Further, the halogenated groupis a group having at least one of hydrogen atoms present in a grouphalogenated by at least one type of halogen atom selected from afluorine atom, a chlorine atom, a bromine atom and an iodine atom, andit may be a group wherein hydrogen atoms are present or not present. Apartially halogenated group is a group having a part of hydrogen atomspresent in the group halogenated, and it is a group wherein hydrogenatoms not substituted by halogen atoms, are present. A perhalogenatedgroup is a group having substantially all hydrogen atoms present in thegroup halogenated, and it is a group wherein substantially no hydrogenatom is present. Further, a perfluoro(partially fluorinated monovalenthydrocarbon) group is a group which is the same as a perfluoromonovalentsaturated hydrocarbon group. Such meanings in the halogenated, thepartially halogenated and the perhalogenated, are similar to themeanings in the fluorinated, the partially fluorinated, the partiallychlorinated and the perfluorinated.

In this specification, the halogenated hydrocarbon group is a grouphaving at least one of hydrogen atoms in a hydrocarbon group substitutedby a halogen atom, and it is preferably a halogenated alkyl group. Thehalogen atom in the halogenated alkyl group is preferably a fluorineatom, a chlorine atom or a bromine atom. Further, as a partiallyhalogenated monovalent saturated hydrocarbon group, a partiallyhalogenated alkyl group is preferred. As a perhalogenated monovalenthydrocarbon group, a perhalogenated alkyl group is preferred. Thehalogen atoms in a perhalogenated alkyl group are preferably composedsolely of fluorine atoms, or fluorine atoms and halogen atoms other thanfluorine atoms (preferably chlorine atoms).

A halogenated bivalent saturated hydrocarbon group is a group having atleast one of hydrogen atoms in a bivalent saturated hydrocarbon groupsubstituted by a halogen atom, and it is preferably a halogenatedalkylene group. As the halogen atom in the halogenated alkylene group, afluorine atom, a chlorine atom or a bromine atom is preferred. As apartially halogenated bivalent saturated hydrocarbon group, a partiallyhalogenated alkylene group is preferred. As a perhalogenated bivalentsaturated hydrocarbon group, a perhalogenated alkylene group ispreferred. The halogen atoms in the perhalogenated alkylene group mayall be fluorine atoms or may comprise fluorine atoms and halogen atomsother than fluorine atoms (preferably chlorine atoms).

In this specification, the hetero atom-containing saturated hydrocarbongroup is a saturated hydrocarbon group which contains a hetero atom notchanged by a fluorination reaction or a hetero atom group not changed bya fluorination reaction. As a bivalent hetero atom not changed by afluorination reaction, an etheric oxygen atom is preferred, and as abivalent hetero atom group not changed by a fluorination reaction,—C—C(O)—C— or —C—SO₂—C— may, for example, be mentioned.

As a hetero atom-containing monovalent saturated hydrocarbon group, analkyl group having an etheric oxygen atom inserted between acarbon-carbon bond, or a cycloalkyl group having an etheric oxygen atominserted between a carbon-carbon bond, may, for example, be mentioned(provided that the etheric oxygen atom in the group may be one or more),and particularly preferred is an alkoxyalkyl group.

As a hetero atom-containing bivalent saturated hydrocarbon group, analkylene group having an etheric oxygen atom inserted between acarbon-carbon bond or at the bonding terminal of the group, or acycloalkylene group having an etheric oxygen atom inserted between acarbon-carbon bond, may, for example, be mentioned, and particularlypreferred is an oxyalkylene group or a polyoxyalkylene group.

As a halogenated (hetero atom-containing monovalent saturatedhydrocarbon) group, a group having at least one of hydrogen atoms in theabove-mentioned hetero atom-containing monovalent saturated hydrocarbongroup substituted by a halogen atom, may be mentioned, and a halogenated(alkoxyalkyl) group is preferred.

As a halogenated (hetero atom-containing bivalent saturated hydrocarbon)group, a group having at least one of hydrogen atoms in theabove-mentioned hetero atom-containing bivalent saturated hydrocarbongroup substituted by a halogen atom, may be mentioned, and a halogenated(oxyalkylene) group or a halogenated (polyoxyalkylene) group ispreferred.

As specific examples of these groups, groups in the following specificcompounds may be mentioned.

R^(A) in the compound (1) is a fluorine-containing bivalent organicgroup which is the same as R^(AF), or a bivalent organic group whichwill be converted to R^(AF) by a fluorination reaction. The carbonnumber of R^(A) is preferably from 1 to 20, particularly preferably from1 to 10. R^(A) may have a linear structure, a branched structure, acyclic structure or a structure partially having a ring.

R^(A) is preferably a bivalent saturated hydrocarbon group, ahalogenated bivalent saturated hydrocarbon group, a heteroatom-containing bivalent saturated hydrocarbon group or a halogenated(hetero atom-containing bivalent saturated hydrocarbon) group, orpreferably such a group containing hydrogen atoms. Further, R^(A) ispreferably a group which is different from the following R^(AF), i.e. agroup which will be converted to R^(AF) by a fluorination reaction.

In a case where R^(A) is a group containing hydrogen atoms, it ispreferably a bivalent saturated hydrocarbon group, a partiallyhalogenated bivalent saturated hydrocarbon group, a heteroatom-containing bivalent saturated hydrocarbon group or a partiallyhalogenated (hetero atom-containing bivalent saturated hydrocarbon)group, and it is preferably an alkylene group, a partially fluorinatedalkylene group, a partially fluorinated (partially chlorinated alkylene)group, an alkylene group containing an etheric oxygen atom (e.g. anoxyalkylene group), a partially fluorinated alkylene group having anetheric oxygen atom (e.g., a partially fluorinated oxyalkylene group), apartially fluorinated (partially chlorinated alkylene) group containingan etheric oxygen atom (e.g., a partially fluorinated (partiallychlorinated oxyalkylene) group). The etheric oxygen atom is preferablyinserted at one or more positions selected from between a carbon-carbonbond, at the bonding terminal with E¹ and at the bonding terminal withE².

Further, in a case where R^(A) is a group other than the above, it ispreferably a group having a fluorine atom in the desired R^(AF)substituted by a monovalent hetero atom group (e.g. a carboxyl group orthe like) which can be converted to a fluorine atom by a fluorinationreaction (e.g. a group having —C(O)— inserted between a carbon-carbonbond of an alkylene group, or the like) or a group having at least oneof carbon-carbon single bonds in the desired R^(AF) substituted by acarbon-carbon double bond or a carbon-carbon triple bond.

It is preferred that hydrogen atoms or fluorine atoms are bonded to thecarbon atoms forming the carbon-carbon double bond, and it isparticularly preferred that hydrogen atoms are bonded. To the carbonatoms forming an unsaturated bond, fluorine atoms will be added by afluorination reaction in a liquid phase, and hydrogen atoms will besubstituted by fluorine atoms. For example, a phenylene group may bechanged to a perfluorocyclohexylene group by a fluorination reaction. Asa specific example of such a group, a cyclohexenylene group, a phenylenegroup, an alkenylene group or an alkynylene group, may, for example, bementioned.

E¹ in the compound (1) is a reactive group which will react with E² toform a bivalent connecting group (E). Such a bivalent connecting group(E) may be a group which may be changed or may not be changed by afluorination reaction.

As the bivalent connecting group (E), —CH₂OCO— or —CH₂OSO₂— (providedthat the direction of such a group is not limited) is, for example,preferred, and —CH₂OCO— is particularly preferred from the viewpoint ofthe usefulness of the desired compound. In a case where E is thepreferred group, E¹ and E² may be such that one of them is —CH₂OH, andthe other is —COX (X is a halogen atom) or —SO₂X.

Now, a detailed description will be made with reference to a case wherethe bivalent connecting group (E) is —CH₂OCO—.

In the present invention, the compound (5) which used to be difficult toobtain, can be produced by carrying out the reaction of the presentinvention by using the compound (1) having a group (R^(A)) having acarbon skeleton corresponding to R^(AF) of the desired compound (5). Thestructure of the compound (1) which can be used in the presentinvention, is not particularly limited.

An example of the compound (5) which used to be difficult to obtain, maybe a compound (5) wherein the structure of R^(AF) is complex, or a lowmolecular weight fluorinated product (5) whereby many by-products areformed by a fluorination reaction. As the low molecular weight compound(5), a fluorinated product of the compound (1) having a molecular weightof at most 200 (preferably a molecular weight of from 50 to 200), may bementioned. Namely, the method of the present invention which is carriedout by using the compound (1) having a molecular weight of at most 200,is one of preferred embodiments.

As the compound (1), the following compound (1—1) wherein E¹ is —CH₂OH,is preferred, the following compound (1-10) wherein R^(A) is R^(AH1) ismore preferred, and the following compound (1-11) wherein R^(A) isR^(AH2), is particularly preferred.HO—CH₂—R^(A)—CH₂OH  (1—1),HO—CH₂—R^(AH1)—CH₂OH  (1-10),HO—CH₂—R^(AH2)—CH₂OH  (1-11).wherein R^(A) has the same meaning as the meaning in the compound (1),and R^(AH1) is a bivalent saturated hydrocarbon group, a halogenatedbivalent saturated hydrocarbon group, a hetero atom-containing bivalentsaturated hydrocarbon group or a halogenated (hetero atom-containingbivalent saturated hydrocarbon) group. R^(AH1) is preferably an alkylenegroup, an oxyalkylene group, a polyoxyalkylene group, a halogenatedalkylene group, a halogenated (oxyalkylene) group or a halogenated(polyoxyalkylene) group. In a case where such a group has a halogenatom, it is preferably at least one member selected from halogen atomsother than a fluorine atom, and as such a halogen atom, a chlorine atom,a bromine atom, or a chlorine atom and a bromine atom, are preferred.

R^(AH2) is an alkylene group, or a group having an etheric oxygen atominserted at one or more positions between a carbon-carbon bond in analkylene group. Particularly preferably, R^(AH2) is an alkylene group,an oxyalkylene group or a polyoxyalkylene group.

In the present invention, it is preferred that one of the compounds (1)and compounds (2) is a compound containing a fluorine atom, and theother is a compound containing no fluorine atom. Particularly from theviewpoint of the usefulness of the compounds, it is preferred that thecompound (1) is a compound containing no fluorine atom (i.e. a compoundhaving a fluorine content of 0 mass %), and the compound (2) is acompound containing a fluorine atom.

The following compounds may be mentioned as specific examples of thecompound (1). The following compounds are known compounds or compoundswhich can easily be prepared by known methods from known compounds.Here, n is an integer of at least 3, preferably from 4 to 10, m is aninteger of at least 1, preferably from 1 to 10, p is an integer of atleast 3, preferably an integer of from 3 to 5, k is an integer of atleast 1, preferably from 1 to 10, and r is an integer of at least 3,preferably an integer of from 3 to 5.

HO(CH₂)_(n)OH,

HO[CH₂CH(CH₃)O]_(m)(CH₂)_(p)OH,

HO(CH₂CH₂O)_(k)(CH₂)_(r)OH.

In the present invention, the compound (1) and the compound (2) arereacted. R^(B) in the compound (2) is a monovalent organic group whichis the same as R^(BF), or a monovalent organic group which will beconverted to R^(BF) by a fluorination reaction. It is preferred toadjust the structure of R^(B) in relation with the structure of R^(A),so that the fluorine content in the resulting compound (3) would be atleast 30 mass %.

The carbon number of R^(B) is preferably from 2 to 20, particularlypreferably from 2 to 10. If the carbon number of R^(B) is 1, there willbe a problem that the recovery of the compound (6), particularly thecompound (6-1), tends to be difficult. Accordingly, the carbon number ofR^(B) is preferably at least 2. R^(B) may have a linear structure, abranched structure, a cyclic structure, or a structure partially havinga ring.

R^(B) may be a monovalent saturated hydrocarbon group, a halogenatedmonovalent saturated hydrocarbon group, a hetero atom-containingmonovalent saturated hydrocarbon group or a halogenated (heteroatom-containing monovalent saturated hydrocarbon) group, and it may bean alkyl group, a fluoroalkyl group, a fluoro(partially chlorinatedalkyl) group, a group having an etheric oxygen atom inserted at one ormore positions between carbon-carbon atoms in an alkyl group, a grouphaving an etheric oxygen atom inserted at one or more positions betweencarbon-carbon atoms in a fluoroalkyl group, or a group having an ethericoxygen atom inserted at one or more positions between carbon-carbonatoms in a fluoro(partially chlorinated alkyl) group.

In a case where R^(B) is a group other than the above, it may be a grouphaving a fluorine atom in the desired R^(BF) substituted by a monovalenthetero atom group which can be converted to a fluorine atom by afluorination reaction, or a group having at least one carbon-carbonsingle bond in the desired R^(BF) substituted by a carbon-carbon doublebond or a carbon-carbon triple bond. It is preferred that hydrogen atomsor fluorine atoms are bonded to the carbon atoms forming thecarbon-carbon double bond, and it is particularly preferred thathydrogen atoms are bonded thereto. As a specific example of such R^(B),a cyclohexenyl group, a phenyl group, an alkenyl group or an alkynylgroup, may be mentioned. Further, as the monovalent hetero atom group, acarboxyl group may be mentioned, and as the group having a monovalenthetero atom group, a group having —C(O)— inserted between acarbon-carbon bond in an alkyl group (—C—C(O)—C—) may be mentioned.

With respect to R^(B) in the present invention, in order to facilitatethe after-mentioned continuous process, R^(A) is preferably a groupcontaining no fluorine atom, and R^(B) is preferably a group containinga fluorine atom.

Further, it is particularly preferred for carrying out theafter-mentioned continuous reaction that R^(B) is the same group asR^(BF), and it is particularly preferred that R^(B) is aperfluoromonovalent organic group. In the case of theperfluoromonovalent organic group, it is preferably aperfluoromonovalent saturated hydrocarbon group, a perfluoro(partiallyhalogenated monovalent saturated hydrocarbon) group, a perfluoro(heteroatom-containing monovalent saturated hydrocarbon) group, or aperfluoro(partially halogenated(hetero atom-containing monovalentsaturated hydrocarbon)) group. Particularly preferred is such a grouphaving at least two carbon atoms.

As the compound (2), a commercial product may be employed, or a compound(6) formed by the after-mentioned method of the present invention, maybe employed.

Further, in the present invention, the fluorine content in the compound(3) (the fluorine content is a proportion of fluorine atoms to themolecular weight of the compound) is adjusted to be at least 30 mass %.By adjusting the fluorine content to be at least 30 mass %, thefluorination reaction in a liquid phase can easily be carried out in ahomogeneous system, and there is a merit that the yield of the reactionwill also be improved.

E² in the compound (2) is a reactive group which will react to E¹ toform a bivalent connecting group (E), and it is particularly preferably—COX or —SO₂X (X is a halogen atom, preferably a chlorine atom or afluorine atom, and in a case where the after-mentioned continuousprocess is carried out, X is a fluorine atom). Further, the compound (2)is preferably a compound (2-1) wherein E² is —COX, more preferably acompound (2-10) wherein R^(B) is the following R^(BF1), particularlypreferably a compound (2-11) wherein R^(B) is R².XCOR^(B)  (2-1),FCOR^(BF1)  (2-10),FCOR²  (2-11).

Here, R^(B) has the same meaning as the meaning in the compound (2),R^(BF1) is a perfluoromonovalent saturated hydrocarbon group or aperfluoro(hetero atom-containing monovalent saturated hydrocarbon)group, and R² is a perfluoroalkyl group, a perfluoro(partiallychlorinated alkyl) group, a perfluoro(alkoxyalkyl) group or aperfluoro(partially chlorinated alkoxyalkyl) group. The carbon number ofR^(BF1) and R^(BF2) is preferably from 2 to 20, particularly preferablyfrom 2 to 10.

The perfluoromonovalent saturated hydrocarbon group may, for example, be—CF₂CF₃, —CF₂CF₂CF₃, —CF₂CF₂CF₂CF₃, —CF₂CClF₂, —CF₂CBrF₂, —CF₂CFClCF₂Cl,—CF(CF₃)₂, —CF₂CF(CF₃)₂, —CF(CF₃)CF₂CF₃ or —C(CF₃)₃.

The perfluoro(hetero atom-containing monovalent saturated) group may,for example, be —CF(CF₃)OCF₂CF₂CF₃, —CF(CF₃)OCF₂CF₂CFClCF₂Cl or—CF(CF₃)OCF₂CF₂Br.

The following compounds may be mentioned as specific examples of thecompound (2).

CF₃CF₂COF,

CF₂ClCFClCF₂COF,

CF₂ClCF₂CFClCOF,

CF₃CF₂CF₂OCF(CF₃)COF,

CF₂ClCFClCF₂CF₂OCF(CF₃)COF,

CClF₂CF₂COF,

CBrF₂CF₂COF,

CF₂BrCF₂OCF(CF₃) COF,

CF₂ClCFClCF₂CF(CF₃)OCF(CF₃)COF,

CF₃CF₂CF₂OCF(CF₃)CF₂OCF(CF₃)COF,

CH₃CH₂CH₂OCF(CF₃)COF,

CH₂ClCHClCH₂COCl,

CF₃CF₂CF₂OCF₂CF₂COF.

The compound (2) may be a known compound or can be produced by a knownmethod from a known compound. For example, CF₃CF₂CF₂OCF(CF₃)COF isreadily available as an intermediate for a perfluoro(alkyl vinyl ether).

The reaction of the compound (1) with the compound (2) may be carriedout by applying a known reaction method and conditions depending uponthe structures of E¹ and E² and their combination. For example, thereaction of the compound (1—1) wherein E¹ is —CH₂OH, with the compound(2-1) wherein E² is —COX, can be carried out under the conditions for aknown esterification reaction. The esterification reaction may becarried out in the presence of a solvent (hereinafter referred to as anesterification reaction solvent), but is preferably carried out in theabsence of any esterification reaction solvent, from the viewpoint ofthe volume efficiency.

In a case where an esterification reaction solvent is employed, it ispreferably dichloromethane, chloroform, triethylamine or a mixed solventof triethylamine and tetrahydrofuran. The amount of the esterificationreaction solvent to be used, is preferably from 50 to 500 mass %, basedon the total amount of the compound (1—1) and the compound (2-1).

By the reaction of the compound (1—1) with the compound (2-1), an acidrepresented by HX, will be formed. In a case where as the compound(2-1), a compound wherein X is a fluorine atom, is used, HF will beformed, and accordingly, an alkali metal fluoride (NaF or KF ispreferred) or a trialkylamine may, for example, be present in thereaction system as a HF scavenger. It is advisable to use a HF scavengerin a case where the compound (1—1) or the compound (2-1) is a compoundwhich is unstable to an acid. Further, in a case where a HF scavenger isnot used, it is preferred to carry out the reaction at a reactiontemperature at which HF can be vaporized, and HF is discharged out ofthe reaction system as carried by a nitrogen stream. The HF scavenger isused preferably in an amount of from 1 to 10 times by mol to thecompound (2-1).

In the esterification reaction, the amount of the compound (2-1) to thecompound (1—1) is preferably from 1.5 to 10 times by mol, particularlypreferably from 2 to 5 times by mol. The lower limit of the temperaturefor the reaction of the compound (1—1) with the compound (2-1) ispreferably −50° C., and the upper limit is preferably whichever is lowerbetween +100° C. and the boiling point of the solvent. Further, thereaction time may suitably be changed depending upon the supply rates ofthe raw materials and the amounts of the compounds to be used in thereaction. The reaction pressure is preferably from 0 to 2 MPa (gaugepressure).

By the reaction of the compound (1) with the compound (2), the compound(3) will be formed. In the compound (3), R^(A) is the same group asR^(A) in the compound (1), and R^(B) is the same group as R^(B) in thecompound (2). E is a bivalent connecting group formed by the reaction ofE¹ with E², and may, for example, be —CH₂OCO— or —CH₂SO₂—.

Further, since the fluorine content in the compound (3) is at least 30mass %, at least one of R^(A), R^(B) and E is a group containingfluorine atoms. Further, the compound (3) preferably has a molecularweight of more than 200 and not more than 1000, so that the fluorinationreaction in a liquid phase in the next step can be carried out smoothly.If the molecular weight is too small, the compound (3) tends to bereadily vaporized, whereby a decomposition reaction in a gas phase islikely to take place during the fluorination reaction. On the otherhand, if the molecular weight is too large, it tends to be difficult tohandle or purify the compound (3).

It is preferred to suitably change the fluorine content depending uponthe type of the liquid phase to be used for the fluorination reaction.Usually, the fluorine content is preferably adjusted to from 30 to 86mass %, particularly preferably from 30 to 76 mass %. The compound (3)having a fluorine content of at least the specified amount, is acompound which is especially excellent in the solubility in the liquidphase for the fluorination reaction and which is excellent in theoperation efficiency for the fluorination reaction and is capable ofaccomplishing the reaction at a high reaction yield.

The compound (3) is preferably a compound (3-1) which will be formed bya reaction of the compound (1—1) with the compound (2-1), morepreferably a compound (3-10) which will be formed by the reaction of thecompound (1-10) with the compound (2-10), particularly preferably acompound (3-11) which will be formed by the reaction of the compound(1-11) with the compound (2-11).RBCOOCH₂—R^(A)—CH₂OCOR^(B)  (3-1),R^(BF1)COOCH₂—R^(AH1)—CH₂OCOR^(BF1)  (3-10),R²COOCH₂—R^(AH2)—CH₂OCOR²  (3-11).

Here, R^(A), R^(B), R^(AH1), R^(BF1), R² and R^(AH2) are as definedabove, and their preferred embodiments are also the same.

The following compounds may be mentioned as specific examples of thecompound (3). Here, the symbols in the formulae are as defined above.

CF₃CF₂COO(CH₂)_(n)OCOCF₂CF₃,

CF₃CF₂COO[CH₂CH(CH₃)O]_(m)(CH₂)_(p)OCOCF₂CF₃,

CF₃CF₂COO(CH₂CH₂O)_(k)(CH₂)OCOCF₂CF₃,

CF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃,

CF₃CF₂CF₂OCF(CF₃)COOCH₂CH(CH₃)O(CH₂)₅OCOCF(CF₃)OCF₂CF₂CF₃,

CF₃CF₂COO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCOCF₂CF₃.

The crude product containing the compound (3) formed by the reaction ofthe compound (1) with the compound (2), may be purified or may be useddirectly for e.g. the subsequent reaction, depending upon the purpose.It is preferred to carry out purification from the viewpoint of carryingout the fluorination reaction smoothly in the subsequent step.

The purification method may, for example, be a method of directlydistilling the crude product, a method of treating the crude productwith a diluted alkali aqueous solution, followed by liquid separation, amethod of extracting the crude product with a suitable organic solvent,followed by distillation or silica gel column chromatography.

In the present invention, the compound (3) is then fluorinated. Thefluorination reaction may be carried out by electrochemical fluorinationor gas phase fluorination, but fluorination in a liquid phase ispreferred. Fluorination in a liquid phase is an excellent method wherebythe compound (4) can be formed in high yield, while preventing thedecomposition reaction of the compound (3). Now, the followingdescription will be made with reference to a case where fluorination iscarried out by a liquid phase fluorination method wherein the reactionwith fluorine is carried out in a liquid phase.

The liquid phase fluorination method is a method which comprisesreacting the compound (3) with fluorine in a liquid phase. The liquidphase may be formed of a substrate or a product of a reaction, and it isusually preferred that a solvent (hereinafter referred to as afluorination reaction solvent) is essential. As the fluorine, fluorinegas, or fluorine gas diluted with an inert gas, is preferably employed.As the inert gas, nitrogen gas or helium gas is preferred, and nitrogengas is particularly preferred from such a viewpoint that it iseconomically advantageous. The amount of fluorine gas in the nitrogengas is not particularly limited, but it is preferably at least 10 vol %,from the viewpoint of efficiency, particularly preferably at least 20vol %.

As the fluorination reaction solvent, a solvent which essentiallycontains a C—F bond without containing a C—H bond, is preferred.Particularly preferred is a perfluoroalkane or an organic solvent havinga known organic solvent containing at least one atom selected from achlorine atom, a nitrogen atom and an oxygen atom in its structure,perfluorinated. Further, as the fluorination reaction. solvent, it ispreferred to employ a solvent which provides a high solubility of thecompound (3). Particularly preferred is a solvent capable of dissolvingat least 1 mass % of the compound (3), and especially preferred is asolvent capable of dissolving at least 5 mass % thereof.

Examples of the fluorinated reaction solvent include the after-mentionedcompound (5), the compound (6), perfluoroalkanes (tradename: FC-72,etc.), perfluoroethers (tradename: FC-75, FC-77, etc.),perfluoropolyethers (tradename: KRYTOX, FOMBLIN, GALDEN, DEMNUM, etc.),chlorofluorocarbons (tradename: FLON LUBE), chlorofluoropolyethers,perfluoroalkylamines (for example, perfluorotrialkylamine, etc.), and aninert fluid (tradename: FLUORINERT). A perfluorotrialkylamine, thecompound (5) or the compound (6) is preferred. It is particularlypreferred to use the compound (5) or the compound (6), whereby work-upprocess after the reaction will be easy.

The amount of the fluorinated reaction solvent is preferably at least 5times by mass, particularly preferably from 10 to 100 times by mass, tothe compound (3).

The reaction system for the fluorination reaction is preferably a batchsystem or a continuous system. Further, the fluorination reaction ispreferably carried out by the method 2 which will be describedhereinafter, from the viewpoint of the reaction yield and selectivity.Further, the fluorine gas is preferably used as diluted by an inert gassuch as nitrogen gas, whether it is carried out by a batch system or bya continuous system.

Method 1: A method wherein the compound (3) and the fluorinated reactionsolvent are charged to a reactor, stirring is initiated, and thereaction is carried out while continuously supplying fluorine gas to thefluorinated reaction solvent at a prescribed reaction temperature andreaction pressure.

Method 2: A method wherein the fluorination solvent is charged into areactor and stirred, and then the fluorine gas, the compound (3) and thefluorination reaction solvent are continuously supplied to thefluorination reaction solvent in a prescribed molar ratio, underprescribed reaction temperature and reaction pressure.

When the compound (3) is supplied in the method 2, it is preferred tosupply the compound (3) which is diluted with the fluorination reactionsolvent, with a view to improving the selectivity and suppressing theamount of by-products. Further, when the compound (3) is diluted with asolvent in the method 2, it is preferred to adjust the amount of thefluorination reaction solvent to the compound (3) to a level of at least5 times by mass, particularly preferably at least 10 times by mass.

In either a batch system or in a continuous system, in the fluorinationreaction, the amount of fluorine (F₂) is preferably adjusted to bealways in an excess amount, to the hydrogen atoms in the compound (3).Namely, the amount of fluorine is preferably at least 1.1 times byequivalent (i.e. at least 1.1 times by mol), particularly preferably atleast 1.5 times by equivalent (i.e. at least 1.5 times by mol), from theviewpoint of the selectivity. The amount of fluorine is preferably in anexcess amount from the beginning to the end of the reaction.Accordingly, when the fluorination solvent is charged to the reactor atthe beginning of the reaction, it is preferred that a sufficient amountof fluorine is preliminarily dissolved in the fluorination solvent.

The fluorination reaction is carried out under such a condition that thebivalent connecting group (E) will not be cleaved. In a case where thebivalent connecting group (E) is —CF₂OCO—, the lower limit of thereaction temperature is preferably −60° C., and the upper limit ispreferably the boiling point of the compound (3). Further, from theviewpoint of the reaction yield, the selectivity and industrialapplicability, the reaction temperature is particularly preferably from−50° C. to +100° C., especially preferably from −20° C. to +50° C. Thereaction pressure for the fluorination reaction is not particularlylimited, and it is particularly preferably from atmospheric pressure to2 MPa (gauge pressure), from the viewpoint of the reaction yield, theselectivity and industrial applicability.

Further, in order to let the fluorination reaction proceed efficiently,it is preferred to add a C—H bond-containing compound to the reactionsystem, or to carry out ultraviolet irradiation. Such is preferablycarried out at a later stage of the fluorination reaction, whereby thecompound (3) present in the reaction system can efficiently befluorinated, and the conversion can remarkably be improved.

The C—H bond-containing compound is preferably an organic compound otherthan the compound (3), particularly preferably an organic hydrocarbon,especially preferably benzene, toluene or the like. The amount of theC—H bond-containing compound is preferably from 0.1 to 10 mol %,particularly preferably from 0.1 to 5 mol %, to the hydrogen atoms inthe compound (3).

Further, the C—H bond-containing compound is preferably added to thereaction system wherein fluorine is present. Further, in a case wherethe C—H bond-containing compound is added, it is preferred to pressurizethe reaction system. The pressure for pressurizing is preferably from0.01 to 5 MPa (gauge pressure). The time for ultraviolet irradiation ispreferably from 0.1 to 3 hours.

By the fluorination reaction of the compound (3), the compound (4) willbe formed. R^(AF) in the compound (4) is a fluorine-containing bivalentorganic group which is the same as or different from R^(A), and whendifferent, it is a group having R^(A) fluorinated. R^(BF) is afluorine-containing monovalent organic group which is the same as ordifferent from R^(B), and when different, it is a group having R^(B)fluorinated.

For example, when R^(A) and R^(B) in the compound (3) are groups havinghydrogen atoms, respectively, R^(AF) and R^(BF) wherein such hydrogenatoms are substituted by fluorine atoms by the fluorination reaction,are groups different from R^(A) and R^(B), respectively. On the otherhand, in a case where R^(A) and R^(B) are groups having no hydrogen atom(for example, in the case of perhalogenated groups), R^(AF) and R^(BF)are the same groups as R^(A) and R^(B), respectively.

R^(AF) and R^(BF) are preferably groups formed by the fluorinationreaction, and in such groups, non-substituted hydrogen atoms may bepresent or may not be present, and they are preferably not substantiallypresent. The amount of hydrogen atoms in R^(AF) and R^(BF) is preferablychanged suitably depending upon the particularly purpose.

In the fluorination reaction in a liquid phase, it is difficult toadjust the positions at which fluorine atoms are introduced.Accordingly, when the compound (3) wherein R^(A) and R^(B) are,respectively, groups having hydrogen atoms, is employed, it is preferredthat R^(AF) and R^(BF) in the compound (4) are groups which aresubstantially perfluorinated.

R^(AF) in the compound (4) is preferably a bivalent saturatedhydrocarbon group, a partially halogenated bivalent saturatedhydrocarbon group, a hetero atom-containing bivalent saturatedhydrocarbon group, or a group having at least one hydrogen atom in R^(A)as a partially halogenated (hetero atom-containing bivalent saturatedhydrocarbon) group, substituted by a fluorine atom by the fluorinationreaction, and particularly preferred is a group having all of hydrogenatoms are substituted by fluorine atoms. Particularly preferably, R^(AF)is a perfluoroalkylene group, or a group having an etheric oxygen atominserted between carbon-carbon atoms in a perfluoroalkylene group.

R^(BF) is preferably a monovalent saturated hydrocarbon group, ahalogenated monovalent saturated hydrocarbon group, a heteroatom-containing monovalent saturated hydrocarbon group, or a grouphaving at least one hydrogen atom in a halogenated (heteroatom-containing monovalent saturated hydrocarbon) group substituted by afluorine atom, and particularly preferred is a group having all ofhydrogen atoms substituted by fluorine atoms, and especially preferredis the same group as in the case where R^(B) is a perfluorinatedmonovalent organic group.

E^(F) is a group which is the same as E, or a group having Efluorinated. As an example of the case where E is a fluorinated group, agroup having at least one hydrogen atom present in E substituted byfluorine, may be mentioned. As E^(F) in a case where E is a group havinga —CH═CH— moiety, a group having such a moiety converted to —CF₂CF₂—,may, for example, be mentioned. Further, since the compound (4) is notof the same structure as the compound (3), at least one selected fromR^(AF), R^(BF) and E^(F), is a group formed by the fluorinationreaction, or a group having R^(A), R^(B) or E changed.

The compound (4) is preferably a compound (4-1) which will be formed byfluorination of the compound (3-1), more preferably a compound (4-10)having the compound (3-10) completely fluorinated, particularlypreferably a compound (4-11) having the compound (3-11) completelyfluorinated.R^(BF)COOCF₂—R^(AF)—CF₂OCOR^(BF)  (4-1),R^(BF1)COOCF₂—R^(AF1)—CF₂OCOR^(BF1)  (4-10),R²COOCF₂—R^(AF2)—CF₂OCOR²  (4-11).

Here, R^(BF), R^(AF), R^(BF1) and R² are as defined above. R^(AF1) is agroup corresponding to R^(AH1), and in a case where hydrogen atoms arepresent in R^(AH1), it is a group having substantially all of thehydrogen atoms substituted by fluorine atoms, and in a case where nohydrogen atom is present in R^(AH1), it is the same group as R^(AH1).R^(AF2) is a group corresponding to R^(AH2) and is a group having all ofhydrogen atoms in R^(AH2) substituted by fluorine atoms.

The following compounds may be mentioned as specific examples of thecompound (4).

CF₃CF₂COOCF₂CF₂CF₂CF₂OCOCF₂CF₃,

CF₃CF₂COOCF₂CF(CF₃)OCF₂CF₂CF₂CF₂OCOCF₂CF₃,

CF₃CF₃CF₂OCF(CF₃)COOCF₂CF(CF₃)OCF₂CF₂CF₂CF₂CF₂OCO—CF(CF₃)OCF₂CF₂CF₃,

CF₃CF₂COOCF₂CF(CF₃)OCF₂CF₂CF₂CF₂CF₂OCOCF₂CF₃,

CF₃CF₂COOCF₂CF₂OCF₂CF₂OCOCF₂CF₃,

CF₃CF₂COO(CF₂)₂O(CF₂)₂OCF(CF₃)CF₂OCOCF₂CF₃.

If a hydrogen atom in the compound (3) is substituted by a fluorine atomin the reaction for fluorinating the compound (3) in a liquid phase, HFwill be formed as a by-product. To remove the by-product HF, it ispreferred to let a HF scavenger coexist in the reaction system or to letthe discharge gas contact with a HF scavenger at the gas outlet of thereactor. As such a HF scavenger, the same ones as mentioned above may beemployed, and NaF is preferred.

In a case where a HF scavenger is permitted to coexist in the reactionsystem, its amount is preferably from 1 to 20 times by mol, particularlypreferably from 1 to 5 times by mol to the total amount of hydrogenatoms present in the compound (3). In the case where the HF scavenger isplaced at the gas outlet of the reactor, it is advisable to arrange (a)a cooler (preferably to maintain the temperature at from 10° C. to roomtemperature, particularly preferably at about 20° C.), (b) a packedlayer of NaF pellets and (c) a cooler (preferably to maintain thetemperature from −78° C. to +10° C., more preferably from −30° C. to 0°C.) in series in the order of (a)-(b)-(c). Further, a liquid returningline to return the condensed liquid from the cooler (c) to the reactor,may be provided.

The crude product containing the compound (4) obtained by thefluorination reaction, may be used directly for the subsequent step, ormay be purified to one having a high purity. The purification methodmay, for example, be a method wherein the crude product is distilleddirectly under atmospheric pressure or reduced pressure.

In the present invention, by the next cleavage reaction of E^(F) of thecompound (4), the compound (5) and/or the compound (6) will be obtained.E^(F) is cleaved to form E^(F1) and E^(F2). The method and conditionsfor the cleavage reaction may be suitably changed depending upon thestructure of the compound (4). In a case where the compound (4) is thecompound (4-1), the cleavage reaction is a dissociation reaction of theester bond i.e. a reaction wherein —CF₂OCO— is cleaved to form two —COF.

The dissociation reaction of the ester bond of the compound (4-1) ispreferably carried out by a pyrolysis or by a dissociation reactioncarried out in the presence of a nucleophilic agent or an electrophilicagent. By such a reaction, the compound (5-1) and the compound (6-1)wherein EF¹ and EF² are —COF, will be formed.

The pyrolysis can be carried out by heating the compound (4-1). It isadvisable to select the reaction type for the pyrolysis depending uponthe boiling point and the stability of the compound (4-1).

For example, in a case where a volatile compound (41) is to bepyrolyzed, a gas phase pyrolysis may be adopted wherein it iscontinuously pyrolyzed in a gas phase, and the outlet gas containing thecompound (5-1) and the compound (6-1) is condensed and recovered.

The reaction temperature for the gas phase pyrolysis is preferably from50 to 350° C., more preferably from 50 to 300° C., particularlypreferably from 150 to 250° C. Further, an inert gas which will not beinvolved directly in the reaction, may be present in the reactionsystem. As such an inert gas, nitrogen gas or carbon dioxide gas may,for example, be mentioned. It is preferred that the inert gas is addedin an amount of from about 0.01 to 50 vol %, based on the compound(4-1). If the amount of the inert gas is large, the recovered amount ofthe product may decrease. The method and conditions for the gas phasepyrolysis are applicable to compounds included in the scope of thecompound (4-1).

On the other hand, in a case where the compound (4-1) is a hardlyvolatile compound, it is advisable to employ a liquid phase pyrolysiswherein it is heated in the state of a liquid in the reactor. In such acase, the reaction pressure is not particularly limited. In a usualcase, the product containing the compound (5-1) is of a low boilingpoint, and accordingly, it is preferred to obtain it by a method by areaction distillation system wherein the product is vaporized andcontinuously withdrawn. Otherwise, a method may be employed whereinafter completion of the heating, the product is withdrawn all at oncefrom the reactor. The reaction temperature for this liquid phasepyrolysis is preferably from 50 to 300° C., particularly preferably from100 to 250° C.

In a case where the pyrolysis is carried out by the liquid phasepyrolysis, it may be carried out in the presence or absence of a solvent(hereinafter referred to as a dissociation reaction solvent). It ispreferably carried out in the absence of any solvent. The dissociationreaction solvent is not particularly limited, so long as it is one whichwill not react with the compound (4-1) and is compatible with thecompound (4-1) and which will not react with the resulting compound(5-1) and compound (6-1). Further, as the dissociation reaction solvent,it is preferred to select one which can easily be separated at the timeof purification. As a specific example of the dissociation reactionsolvent, preferred is an inert solvent such as a perfluorotrialkylamineor a perfluoronaphthalene, or a chlorofluorocarbon, specifically achlorotrifluoroethylene oligomer having a high boiling point (forexample, tradename: FLON LUBE). The amount of the dissociation reactionsolvent is preferably from 0.10 to 10 times by mass, to the compound(4).

Further, in a case where the dissociation reaction of an ester bond iscarried out by reacting the compound (4-1) with a nucleophilic agent oran electrophilic agent in a liquid phase, such a reaction may be carriedout in the presence or absence of the dissociation reaction solvent, andit is preferably carried out in the absence of any solvent. As thenucleophilic agent, F⁻ is preferred, and particularly preferred is F⁻derived from an alkali metal fluoride. As the alkali metal fluoride,NaF, NaHF₂, KF or CsF may be used, and among them, NaF is particularlypreferred from the viewpoint of the economical efficiency. It isparticularly preferred to carry out the dissociation reaction of theester bond in the absence of any medium, since the compound (4-1) itselfserves as a solvent, and it is not required to separate a solvent fromthe reaction product.

Further, in a case where the dissociation reaction of the ester bond iscarried out by using F⁻ as a nucleophilic agent, F⁻ will benucleophilically added to the carbonyl group present in the ester bondin the compound (4-1), whereby R^(BF)CF₂O⁻ will be detached, and thecompound (5-1) will be formed. Further, F⁻ will be detached fromR^(BF)CF₂O⁻ to form the compound (6-1). The detached F⁻ will react withanother molecule of the compound (4) in a similar manner. Accordingly,the nucleophilic agent initially employed for the reaction may be in acatalytic amount or in an excess amount. The amount of the nucleophilicagent such as F⁻ is preferably from 1 to 500 mol %, more preferably from1 to 100 mol %, particularly preferably from 5 to 50 mol %, based on thecompound (4-1). The reaction temperature is preferably from −30° C. tothe boiling point of the solvent or the compound (4-1), more preferablyfrom −20° C. to 250° C. This method is also preferably carried out whileconducting distillation by a reaction apparatus having a distillationcolumn.

From the reaction product of the dissociation reaction of the ester bondof the compound (4-1), the compound (5-1) and/or the compound (6-1) willbe obtained; from the reaction product of the dissociation reaction ofthe ester bond of the compound (4-10), the compound (5-10) and/or thecompound (6-10) will be obtained; and from the reaction product of thedissociation reaction of the ester bond of the compound (4-11), thecompound (5-11) and/or the compound (6-11) will be obtained.FCO—R^(AF)—COF  (5-1),R^(BF)—COF  (6-1),FCO—R^(AF1)—COF  (5-10),R^(BF1)COF  (6-10),FCO—R^(AF2)—COF  (5-11), R²COF  (6-11).

The following compounds may be mentioned as specific examples of thecompound (5-1).

FCOCF₂CF₂COF,

FCOCF(CF₃)OCF₂CF₂CF₂COF,

FCOCF(CF₃)OCF₂CF₂CF₂CF₂COF,

FCOCF₂OCF₂COF,

FCOCF₂O(CF₂)₂OCF(CF₃)COF.

The following compounds may be mentioned as specific examples of thecompound (6-1).

CF₃CF₂COF,

CF₂ClCFClCF₂COF,

CF₂ClCF₂CFClCOF,

CF₃CF₂CF₂OCF(CF₃)COF,

CF₂ClCFClCF₂CF₂OCF(CF₃)COF,

CClF₂CF₂COF,

CBrF₂CF₂COF,

CF₂BrCF₂OCF(CF₃)COF,

CF₂ClCFClCF₂CF(CF₃)OCF(CF₃)COF,

CF₃CF₂CF₂OCF(CF₃)CF₂OCF(CF₃)COF,

CF₃CF₂CF₂OCF₂CF₂COF.

Among the compound (5) and/or the compound (6) obtainable by the methodof the present invention, a compound (5-1) and/or a compound (6-1)having a partial structure of “C¹F—C²—COF” at a molecular terminal, canbe led to a fluororesin raw material by converting the molecularterminal to “C¹═C²” (wherein 1 and 2 in C¹ and C² are numeralsspecifying the carbon atoms) by a known reaction (Methods of OrganicChemistry, 4, Vol. 10b, Part 1, p. 703, etc.). Such a compound is acompound useful as a precursor for a fluororesin raw material.

For example, in a case where the method of the present invention isapplied to the following compound, a useful fluororesin raw material canbe produced.

For example, a compound (1-12) and a compound (2-12) are reacted toobtain a compound (3-12). The compound (3-12) is fluorinated in a liquidphase to obtain a compound (4-12). Then, the ester bond of the compound(4-12) is subjected to a dissociation reaction to obtain a compound(5-12) and/or a compound (2-12).HO(CH₂)₄OH  (1-12),FCOCF₂CF₃  (2-12),CF₃CF₂COO(CH₂)₄OCOCF₂CF₃  (3-12),CF₃CF₂COO(CF₂)₄OCOCF₂CF₃  (4-12),FCO (CF₂)₂COF  (5-12).

The compound (5-12) can be led to a useful fluororesin raw material(CF₂═CFO(CF₂)₃COOCH₃) by the following route. Here, HFPO representshexafluoropropylene oxide.FCO(CF₂)₂COF (5-12)+HFPO+CsF→FCOCF(CF₃)O(CF₂)₃COF→FCOCF(CF₃)O(CF₂)₃COF→pyrolysis→CF₂═CFO(CF₂)₃COFCF₂═CFO(CF₂)₃COF+CH₃OH→CF₂═CFO(CF₂)₃COOCH₃

Further, a compound (1-3) and a compound (2-13) are reacted to obtain acompound (3-13). The compound (3-13) is fluorinated in a liquid phase toobtain a compound (4-13). Then, the ester bond of the compound (4-13) issubjected to a dissociation reaction to obtain a compound (5-13) and/ora compound (2-13). The compound (5-13) can also be led to a usefulfluororesin raw material by the same route as mentioned above.HOCH₂CH(CH₃)O(CH₂)₄OH  (1-13),FCOCF₂CF₃  (2-13),CF₃CF₂COOCH₂CH(CH₃)O(CH₂)₄OCOCF₂CF₃  (3-13),CF₃CF₂COOCF₂CF(CF₃)O(CF₂)₄OCOCF₂CF₃  (4-13),FCOCF(CF₃)O(CF₂)₃COF  (5-13),

Further, a compound (1-14) and a compound (2-14) are reacted to obtain acompound (3-14). The compound (3-14) is fluorinated in a liquid phase toobtain a compound (4-14). Then, the ester bond of the compound (4-14) issubjected to a dissociation reaction to obtain a compound (5-14) and/ora compound (2-14). The compound (5-14) is a compound present as atautomer of lactone.HO(CH₂)₂O(CH₂)₂OH  (1-14),FCOCF₂CF₃  (2-14),CF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃  (3-14),CF₃CF₂COO(CF₂)₂O(CF₂)₂OCOCF₂CF₃  (4-14),FCOCF₂OCF₂COF  (5-14).

The following intermediate compounds in the above production routes arenovel compounds useful as fluororesin raw materials.CF₃CF₂COO(CH₂)₄OCOCF₂CF₃  (3-12),CF₃CF₂COOCH₂CH(CH₃)O(CH₂)₄OCOCF₂CF₃  (3-13),CF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃  (3-14),CF₃CF₂CF₂OCF(CF₃)COOCH₂CH(CH₃)O(CH₂)₅—OCOCF(CF₃)OCF₂CF₂CF₃  (3-15),CF₃CF₂COO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCOCF₂CF₃  (3-16),CF₃CF₂COOCF₂CF₂CF₂CF₂OCOCF₂CF₃  (4-12),CF₃CF₂COOCF₂CF(CF₃)OOCF₂CF₂CF₂CF₂OCOCF₂CF₃  (4-13),CF₃CF₂COOCF₂CF₂OCF₂CF₂OCOCF₂CF₃  (4-14),CF₃CF₂CF₂OCF(CF₃)COOCF₂CF(CF₃)OCF₂(CF₂)₃—CF₂OCOCF(CF₃)OCF₂CF₂CF₃  (4-15),CF₃CF₂COO(CF₂)₂O(CF₂)₂OCF(CF₃)CF₂OCOCF₂CF₃  (4-16).

Further, among compounds (5), the following compound (5-2) is aparticularly useful compound wherein both terminals of the molecule canbe converted to fluorinated vinyl groups.FCO-Q^(F1)-R^(AF)-Q^(F2)—COFtm (5-2)wherein

R^(AF): as defined above, and the preferred embodiments are also thesame as mentioned above.

Q^(F1), Q^(F2): each represents —CF(OF₃)— or —CF₂CF₂—.

The compound (5-2) is obtained together with the compound (6-1) from areaction product, obtained by reacting a compound (1-2) and a compound(2-1) to obtain a compound (3-2), fluorinating the compound (3-2) in aliquid phase to obtain a compound (4-2) and subjecting the ester bond ofthe compound (4-2) to a dissociation reaction.HOCH₂-Q¹-R^(A)-Q²-CH₂OH  (1-2),XCOR^(B)  (2-1),R^(B)COOCH₂-Q¹-R^(A)-Q²-CH₂OCOR^(B)  (3-2),R^(BF)COOCF₂-Q^(F1)-R^(AF)-Q^(F2)-C_(F2)OCORB^(F)  (4-2),FCO-Q^(F1)-R^(AF)-QF²-COF  (5-2),R^(BF)-COF  (6-1).wherein

R^(A), R^(B), R^(AF), R^(BF), X, Q^(F1), Q^(F2): as defined above.

Q¹, Q²: they may be the same or different, and each represents —CH(CH₃)—or —CH₂CH₂—.

Further, the above Q¹ and Q² are preferably —CH(CH₃)—, and Q^(F1) andQ^(F2) are preferably —CF(CF₃)—.

In the method of the present invention, from the reaction product afterthe dissociation reaction of the ester bond, only the compound (5), onlythe compound (6), or both of the compounds (5) and (6), may be obtained.For example, in a case where the reaction of the present invention iscarried out by using a compound (1—1) wherein R^(A) is a bivalentorganic group containing hydrogen atoms, and a compound (2-1) whereinR^(B) is a perhalogenated monovalent organic group, a compound (5-1)wherein R^(A) is fluorinated, can be obtained. Further, in a case wherethe reaction of the present invention is carried out by using a compound(1—1) wherein R^(A) is a perhalogenated bivalent organic group and acompound (2-1) wherein R^(B) is a monovalent organic group containinghydrogen atoms, a compound (6-1) having stoichiometrically two moleculesfluorinated, will be obtained.

Further, in the method of the present invention, when the resultingcompound (6) has the same structure as the compound (2), such a compound(6) is used as the compound (2), whereby the compound (5) can becontinuously produced. For example, a method may be mentioned wherein apart or whole of the formed compound (6-1) is used as the compound (2-1)and reacted with the compound (1—1). In a case where such a method iscarried out, it is preferred that the carbon number of R^(BF) isadjusted to be at least 2, more preferably from 2 to 20, particularlypreferably from 4 to 10.

The compound (5-2) obtained by the above method can be converted to acompound (7-2) by a pyrolysis.CF₂═CF—R^(AF)—CF═CF₂  (7-2).

Here, R^(AF) is as defined above, and the preferred embodiments are alsothe same as mentioned above. The pyrolysis reaction can be carried outby a known method disclosed in e.g. J. Org. Chem., 34, 1841 (1969).

The following compounds may be mentioned as specific examples of thecompound (7-2).CF₂═CFO(CF₂)₂CF═CF₂,CF₂═CFOCF₂CF═CF₂.

According to the method of the present invention, variousfluorine-containing compounds may be produced by using a compound (1)and a compound (2) which are materials available inexpensively.Especially, by using the compound (1—1) and the compound (2-1) variousdiacyl fluoride compounds and a compound having a fluorinated vinylgroups at both terminals can be produced.

As the compound (1) and the compound (2) to be used as the raw materialsin the method of the present invention, various compounds different inthe structures of R^(A) and R^(B), are commercially sold and availableinexpensively. And, according to the method of the present invention,from these raw material compounds, fluorine-containing compounds such asa diacyl fluoride compound and a compound having fluorinated vinylgroups at its both terminals, can be produced by a short process and inhigh yield. Further, by employing the method of the present invention, alow molecular weight fluorine-containing compound which used to bedifficult to obtain by a conventional method, or a fluorine-containingcompound having a complex structure, can easily be prepared. Further,the method of the present invention is not limited to the compoundsdisclosed as the above specific examples, and it is a method excellentin general applicability and applicable to various compounds, whereby afluorine-containing compound having an optional skeleton can freely beproduced. Further, by selecting the structures of R^(A) and R^(B), it ispossible to carry out an efficient method wherein the product isre-used.

Further, according to the present invention, a novel intermediate whichcan be used as a raw material for a fluororesin, will be provided.

EXAMPLES

Now, the present invention will be described in further detail withreference to Examples. However, the present invention is by no meansthereby restricted. In the following, gas chromatography is representedby GC, and the mass analysis of gas chromatography will be representedby GC-MS. Further, the purity determined by the peak area ratio of GC isrepresented by GC purity, and the purity obtained from the peak arearatio of the NMR spectrum, will be represented by NMR purity. For thequantitative analysis by ¹⁹F-NMR, perfluorobenzene was used as theinternal standard sample. Further, tetramethylsilane was represented byTMS, and dichloropentafluoropropane is represented by R-225, and asR-225, AK225, tradename, manufactured by Asahi Glass Company, Limited,was used. Further, NMR spectrum data are shown within the apparentchemical shift range. The standard value for the standard substanceCDCl₃ in ¹³C-NMR was set to be 76.9 ppm.

Example 1 Example 1—1 Preparation Example for CF₃CF₂COO(CH₂)₄OCOCF₂CF₃

HO(CH₂)₄OH (200 g) was put into a flask and stirred while bubblingnitrogen gas. While maintaining the internal temperature from at 25 to30° C., FCOCF₂CF₃ (800 g) was bubbled over a period of 2.5 hours. Aftercompletion of the dropwise addition, stirring was continued at roomtemperature for 15 hours, whereupon the crude liquid was recovered in aseparating funnel. A NaHCO₃ saturated aqueous solution (500 ml) wasadded thereto at an internal temperature of at most 20° C. andneutralized twice. Further, the organic phase was washed three timeswith water (1 ), and the organic phase was recovered. After drying overmagnesium sulfate, filtration was carried out to obtain a crude liquid.

The crude liquid was purified by silica gel column chromatography(developing solvent: R-225), and then, the crude liquid was concentratedby an evaporator, followed by distillation under reduced pressure,whereby 254.79 g of a fraction of 91 to 93° C./1.0 to 1.3 kPa (absolutepressure) was obtained. The GC purity was 99%. Further, the NMR spectrumof the fraction was measured to confirm that the main component was theabove-identified compound.

NMR spectrum of the fraction:

¹H-NMR(300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.85-1.89 (m,4H), 4.41-4.45 (m, 4H).

¹⁹F-NMR(282.65 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −83.0(6F),−121. 4(4F).

Example 1-2 Preparation Example for CF₃CF₂COO(CF₂)₄OCOCF₂CF₃

Into a 3000 ml autoclave made of nickel, R-113 (3232 g) was added,stirred and maintained at 25° C. At the gas outlet of the autoclave, acooler maintained at −10° C. was installed. After supplying nitrogen gasfor 1.5 hours, fluorine gas diluted to 20 vol % with nitrogen gas(hereinafter referred to as 20% fluorine gas) was supplied at 8.49 /hfor 2.3 hours.

Then, while supplying 20% fluorine gas at the same flow rate, a solutionhaving CF₃CF₂COO(CH₂)₄OCOCF₂CF₃ (80 g) obtained in Example 1—1dissolvedin R-113 (800 g), was injected over a period of 45.7 hours. Further, 20%fluorine gas was supplied at the same flow rate for 0.5 hour, andfurther nitrogen gas was supplied for 3.0 hours. The formed productcontained the above-identified compound as the main product, and the¹⁹F-NMR yield was 92%.

¹⁹F-NMR (376.0 MHz, solvent CDCl₃, standard:CFCl₃) δ (ppm): −83.8(6F),−87.3(4F), −122.6(4F), −126.6(4F).

Example 1-3 Preparation Example for FCOCF₂CF₂COF by a DissociationReaction of an Ester Bond in Liquid Phase

CF₃CF₂COO(CF₂)₄OCOCF₂CF₃(5.0 g) obtained in Example 1-2 was chargedtogether with 0.4 g of NaF powder into a flask and heated at 100° C. for0.25 hour in an oil bath while vigorously stirring. At an upper portionof the flask, a container for gas recovery was installed. After cooling,3.46 g of a gaseous sample was recovered. By the NMR spectrum, it wasconfirmed that CF₃CF₂COF and the above-identified compound were the maincomponents. The yield of the above-identified compound was 52.4%.

¹⁹F-NMR(282.65 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): 25.3(2F),−118.2(4F).

Example 2 Example 2-1 Preparation Example for TsOCH(CH₃)CH₂OCH₂Ph(wherein Ts is a p-toluene Sulfonyl Group, and Ph is a Phenyl Group, andthe Same Applies Hereinafter)

Into a four necked flask, HOCH(CH₃)CH₂OCH₂Ph (50.0 g) was charged, andpyridine (150 ml) was added, followed by stirring. While cooling in anice bath and maintaining the internal temperature at 5° C., p-toluenesulfonic acid chloride (63.1 g) was gradually added over a period of 1hour. The mixture was added to water (165 ml), and dichloromethane (165ml) was added for extraction, whereupon the liquids separated into twolayers were separated. The organic layer was washed with NaHCO₃ (165 ml)and further washed three times with water (130 ml). It was dried overmagnesium sulfate, filtered and then concentrated by an evaporator.Precipitated white crystals were collected by filtration and washed withhexane to obtain the above-identified compound (83.2 g).

¹H-NMR(3004 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.31(d, J=6. 3Hz, 3H), 2.40 (s, 3H), 3.46 (m, 2H), 4.41 (d, J=1.8 Hz, 2H), 4.73 (m,1H) 7.19-7.34 (m, 7H) 7.75-7.89 (m, 2H)

Example 2-2 Preparation Example for HO(CH₂)₄OCH(CH₃)CH₂OCH₂Ph

HO(CH₂)₄OH (37 g), potassium hydroxide (23 g) and dioxane (200 ml) werecharged into a four necked flask and heated to an internal temperatureof 102° C. to dissolve potassium hydroxide. A solution ofTsOCH(CH₃)CH₂OCH₂Ph (63.7 g) obtained in Example 2-1 in dioxane (65 ml),was dropwise added over a period of 1 hour and stirred for 4 hours. Themixture was left to cool, then added to water (350 ml) and extractedthree times with dichloromethane (100 ml). The organic layer was washedwith water (20 ml). It was dried over magnesium sulfate, filtered andthen concentrated by an evaporator to obtain a crude product (52 g). Itwas purified by silica gel column chromatography to obtain theabove-identified compound (27.6 g).

¹H-NMR (300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.15 (d,J=6.2 Hz, 3H), 1.64 (m, 4H), 2.98 (bs, 1H), 3.62-3.68 (m, 7H), 4.53 (d,J=2.3 5 Hz, 2H), 7.23-7.29 (m, 5H).

Example 2-3 Preparation Example for HO(CH₂)₄CH(CH₃)CH₂OH

A round bottom flask was flushed with argon, and 5% palladium-carbonpowder (1.5 g) was charged. Ethanol (100 ml) andHO(CH₂)₄OCH(CH₃)CH₂OCH₂Ph (15.2 g) obtained in Example 2—2 were added,then deaerated and flushed with nitrogen. The mixture was stirred atroom temperature for 17 hours and then filtered through cerite. Thefiltrate was concentrated by an evaporator to obtain theabove-identified compound (8.65 g).

¹H-NMR(300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.11 (q, J=6.2Hz, 3H), 1.68 (m, 4H), 2.48 (bs, 2H), 3.41-3.68 (m, 7H)

Example 2-4 Preparation Example for CF₃CF₂COO(CH₂)₄OCH(CH₃)CH₂OCOCF₂CF₃

HO(CH₂)₄OCH(CH₃)CH₂OH (18.8 g) obtained in Example 2-3 was put into around bottom flask and stirred while maintaining the internaltemperature at 30° C. Together with nitrogen, CF₃CF₂COF (276 g) wassupplied over 6 hours while maintaining the internal temperature at 30°C. After completion of the reaction, stirring was continued for 2 hoursat an internal temperature of 30° C. while supplying nitrogen gas,whereupon a 5% NaHCO₃ aqueous solution (300 ml) was added at an internaltemperature of at most 15° C.

The obtained crude liquid was subjected to liquid separation. The lowerlayer was washed twice with water (100 ml), dried over anhydrousmagnesium sulfate and then filtered to obtain a crude liquid. The crudeliquid was purified by silica gel column chromatography (developingsolvent: R-225) to obtain the above-identified compound (25.9 g). The GCpurity was 99%.

¹H-NMR(300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.20(d, J=6.3Hz, 3H), 1.56˜1.68(m, 2H), 1.78˜1.87(m, 2H), 3.42˜3.60(m, 2H),3.66˜3.76(m, 1H), 4.26˜4.42(m, 4H).

¹⁹F-NMR (282.7 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −83.0(3F), −83.0(3F), −121.4(2F), −121.5(2F)

Example 2-5 Preparation Example for CF₃CF₂COO(CF₂)₄OCF(CF₃)CF₂OCOCF₂CF₃

Into a 500 ml autoclave made of nickel, R-113 (313 g) was charged,stirred and maintained at 25° C. At the gas outlet of the autoclave, acooler maintained at 20° C., a packed layer of NaF pellets and a coolermaintained at −10° C. were installed in series. Further, a liquidreturning line was installed to return a liquid condensed from thecooler maintained at −10° C. to the autoclave. After supplying nitrogengas for 1.0 hour, 20% fluorine gas was supplied at a flow rate of 10.10l/hr for 1.1 hours. Then, while supplying 20% fluorine gas at the sameflow rate, a solution having CF₃CF₂COO(CH₂)₄OCH(CH₃)CH₂OCOCF₂CF₃ (4.95g) obtained in Example 2-4 dissolved in R-113 (100 g), was injected overa period of 5.5 hours.

Then, while supplying 20% fluorine gas at the same flow rate, thetemperature within the reactor was raised from 25° C. to 40° C., and atthe same time, a R-113 solution (9 ml) containing 0.01 g/ml of benzene,was injected. The injection inlet for benzene and the outlet valve ofthe autoclave were closed, and when the pressure became 0.20 MPa (gaugepressure), the fluorine gas inlet valve of the autoclave was closed.Further, stirring was continued for 0.4 hour. Then, the pressure in thereactor was returned to normal pressure, and while maintaining thetemperature at 40° C., the above-mentioned benzene solution (6 ml) wasinjected. The operation of closing the benzene injection inlet and theoutlet valve of the autoclave and, when the pressure became 0.20 MPa(gauge pressure) closing the fluorine gas inlet valve of the autoclave,followed by stirring for 0.4 hour, was repeated four times.

The total amount of benzene injected was 0.336 g, and the total amountof R-113 injected was 33 ml. Further, nitrogen gas was supplied for 1.5hours. The ¹⁹F-NMR yield of the above-identified compound contained inthe product, was 94%.

¹⁹F-NMR (376.0 MHz, solvent CDCl₃, standard:CFC₃) δ (ppm): −80.4(3F),−81.0(2F), −83.3(3F), −83.4(3F), −86.8(2F), −86.9(2F), −122.1(4F),−125.9(2F), −126.2(2F), −145.6(1F).

Example 2-6 Preparation Example for FCOCF(CF₃)O(CF₂)₃COF by aDissociation Reaction of an Ester Bond in a Liquid Phase

CF₃CF₂COO(CF₂)₄OCF(CF₃)CF₂OCOCF₂CF₃ (0.6 g) obtained in Example 2-5 wascharged together with NaF powder (0.008 g) into a flask and heated at100° C. for 5.66 hours in an oil bath, while vigorously stirring. At anupper portion of the flask, a liquid sample (0.65 g) was recoveredthrough a reflux condenser having the temperature adjusted to 90° C.From the NMR spectrum, it was confirmed that the above-identifiedcompound was the main component. The yield was 77.1%.

¹⁹F-NMR(376 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): 26.5(1F),25.0(1F), −78.3˜78.8(1F), −82.1(3F), −86.0˜−86.4(1F), −118.5 (2F),−126.6(2F), −131.0(1F).

Example 3 Example 3-1

Preparation Example for HOCH₂CH(CH₃)O(CH₂)₅OH

CH₃CH(OH)CH₂OCH₂Ph (50.0 g) and pyridine (150 ml) were put into a flask,and under cooling with ice, p-toluenesulfonic acid chloride (63.2 g) wasadded over a period of 30 minutes. The mixture was stirred at roomtemperature for 4 days, and then water (150 ml) was added, followed byextraction twice with dichloromethane (100 ml). The extracted organicphase was washed twice with a KHCO₃ saturated aqueous solution (100 ml)and twice with water (100 ml), dried over magnesium sulfate, filteredand further concentrated to obtain PhCH₂OCH₂CH(CH₃)OTs (71.2 g).

Into another flask, KOH (25.8 g), HO(CH₂)₅OH (47.9 g) and dioxane (200ml) were charged and stirred at 90° C. until KOH was dissolved. Then,from a dropping funnel, PhCH₂OCH₂CH(CH₃)OTs (71.2 g) and dioxane (75 ml)were added at 90° C. over a period of 20 minutes. After further stirringat 80° C. for 20 hours, water (350 ml) was added. Extraction withdichloromethane (100 ml) was carried out three times, and the extractedorganic phase was washed with water (150 ml), then dried over anhydrousmagnesium sulfate, filtered and further concentrated. The concentratedliquid was purified by silica gel column (eluent: hexane/ethyl acetate)to obtain PhCH₂OCH₂CH(CH₃)O(CH₂)₅OH(20.8 g).

Into a flask, 5% palladium-carbon powder (4 g) and ethanol (200 ml) werecharged, and nitrogen was supplied for 1 hour. The interior was vacuumedand flushed with hydrogen, whereupon PhCH₂OCH₂CH(CH₃)O(CH₂)₅OH (18 ml)was added by a syringe and stirred for 24 hours. The crude liquid wasfiltered and concentrated to obtain the above-identified compound (11.9g).

Example 3-2 Preparation Example forCF₃CF₂CF₂OCF(CF₃)COOCH₂CH(CH₃)O(CH₂)₅OCOCF(CF₃)OCF₂CF₂CF₃

HOCH₂CH(CH₃)O(CH₂)₅OH (11.8 g) obtained in Example 3-1 was put into aflask, and as a HF scavenger, ethylamine (30.3 g) was added and stirred.While maintaining the internal temperature to a level of at most 15° C.,CF₃CF₂CF₂OCF(CF₃)COF (49.8 g) was dropwise added over a period of 1hour. After completion of the dropwise addition, the mixture was stirredat room temperature for 2 hours, and excess CF₃CF₂CF₂OCF(CF₃)COF wasdistilled off under reduced pressure. The product was washed with water(50 ml) and then washed three times with a 0.1N hydrochloric acidaqueous solution (30 ml) to remove the remaining triethylamine. Further,the organic layer was washed three times with a KHCO₃ saturated aqueoussolution (30 ml), dried over magnesium sulfate and then filtered toobtain a liquid (53.0 g) having a GC purity of 97%.

The NMR spectrum was measured, and it was confirmed that the maincomponent was the above-identified compound and a mixture ofdiastereomers.

¹H-NMR(300.4 MHz, solvent CDCl₃, standard:TMS) δ (ppm): 1.19(d, J=6.3Hz, 3H), 1.39-1.49 (m, 2H), 1.54-1.63 (m, 2H), 1.71-1.80 (m, 2H),3.39-3.53(m, 2H), 3.66-3.72(m, 1H), 4.21-4.46(m, 4H).

¹⁹F-NMR (282.7 MHz, solvent CDCl₃, standard:CFCl₃) δ (ppm): −80.9(2F),−82.3(6F), −83.1(6F), −87.4(2F), −130.7(4F), −132.7(2F).

Example 3—3 Preparation Example forCF₃(CF₂)₂OCF(CF₃)COOCF₂CF(CF₃)O(CF₂)₅OCOCF(CF₃)OCF₂CF₂CF₃

Into a 500 ml autoclave made of nickel, R-113 (312.2 g) was added andstirred, and the internal temperature was adjusted to 25° C. At the gasoutlet of the autoclave, a cooler maintained at 25° C., a packed layerof NaF pellets and a cooler maintained at −8° C., were installed inseries. Further, a liquid returning line was installed in order toreturn a liquid condensed from the cooler maintained at −8° C. to theautoclave. After supplying nitrogen gas for 1 hour, 20% fluorine gas wassupplied at a flow rate of 11.0 /hr for 1 hour, and while supplying atthe same flow rate, a R-113 (200 g) solution of the liquid product (10g) obtained in Example 3-2, was injected over a period of 6 hours.

Then, the internal temperature was raised to 40° C., and while supplying20% fluorine gas at the above-mentioned flow rate, a R-113 solution ofbenzene (0.01 g/ml) was injected. The outlet valve of the autoclave wasclosed, and when the pressure became 0.20 MPa (gauge pressure), theinlet valve of the autoclave was closed, and stirring was continued for20 minutes. Further, the same operation was repeated five times. Duringthis period, benzene was supplied in a total amount of 0.27 g, and R-113was supplied in a total amount of 42.1 g. Thereafter, nitrogen gas wassupplied for 1 hour, and the reaction mixture was taken out bydecantation. The obtained crude liquid was concentrated by an evaporatorand quantified, whereby the ¹⁹F-NMR yield was 70%. The crude liquid wasdistilled under reduced pressure to obtain the above-identifiedcompound. The product was a mixture of diastereomers.

¹⁹F-NMR (282.7 MHz, solventCDCl₃/C₆F₆, standard:CFCl₃) δ (ppm):−79.2˜−80.7(7F), −81.5˜−82.0(12F), −85.9˜−87(6F), −122.4(2F),−125.3(4F), −129.6(4F), −131.4(2F), −144.9(1F).

Example 3—3 Preparation Example for FCOCF(CF₃)O(CF₂)₄COF

The product (5 g) obtained in Example 3-2 was charged into a 30 ml flaskequipped with a reflux condenser of 80° C., and potassium fluoride (0.06g) was added, whereupon while stirring under heating at 150° C., theformed gas was cooled to −78° C. and recovered in a glass trap. When thereaction proceeded, and the liquid in the flask was all disappeared, thereaction was terminated. In the glass trap, 4.8 g of the product wasobtained.

As a result of the GC analysis, it was confirmed thatCF₃CF₂CF₂OCF(CF₃)COF and FCOCF(CF₃)O(CF₂)₄COF were formed in a ratio of2:1 (molar ratio).

Example 3-4 Preparation Example for CF₂═CFOCF₂CF₂CF═CF₂ by Pyrolysis

In the same manner as the method disclosed in J. Org. Chem., 34, 1841(1969), pyrolysis was carried out by using FCOCF(CF₃)O(CF₂)₄COF obtainedby the reaction of Example 3—3, and formation of the above-identifiedcompound was confirmed by GC.

Example 4 Example 4-1 Preparation Example forCF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃ by an Esterification Reaction

HO(CH₂)₂O(CH₂)₂OH(40 g) was put into a flask and stirred whilemaintaining the internal temperature at 30° C. While maintaining theinternal temperature of the flask at 30° C., nitrogen and CF₃CF₂COF (388g) were supplied over a period of 1.5 hours. After completion of thereaction, while supplying nitrogen gas, stirring was continued at aninternal temperature of 30° C. for 2 hours, and then the internaltemperature of the flask was brought to at most 15° C., whereupon 5%NaHCO₃ (300 ml) was added.

The obtained crude liquid was subjected to liquid separation, and thelower layer was washed twice with 100 ml of water, dried over magnesiumsulfate and then filtered to obtain a crude liquid. By distillationunder reduced pressure, the above-identified compound (91.8 g) wasobtained as a fraction of 81 to 84° C./1.3 kPa (absolute pressure). TheGC purity was 99%.

¹H-NMR(300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm):3.77˜3.80(m,4H), 4.50˜4.53(m, 4H).

¹⁹F-NMR (282.7 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm): −83.0(6F),−121.6 (4F).

Example 4-2 Preparation Example for CF₃CF₂COO(CF₂)₂O(CF₂)₂OCOCF₂CF₃ by aFluorination Reaction

In the same autoclave as in Example 2-5, R-113 (312 g) was added, andpreparation was made under the same condition except that 20% fluorinegas was supplied at a flow rate of 9.47 /hr for 1 hour. Then, whilesupplying 20% fluorine gas at the same flow rate, a solution havingCF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃ (7.0 g) obtained in Example 4-1dissolved in R-113 (140 g), was injected over a period of 4.9 hours.

Then, while supplying 20% fluorine gas at the same flow rate andmaintaining the pressure of the reactor at 0.15 MPa (gauge pressure), aR-113 solution (9 ml) containing 0.01 g/ml of benzene, was injectedwhile raising the temperature from 25° C. to 40° C., and the benzeneinjection inlet of the autoclave was closed, and stirring was continuedfor 0.3 hour. Then, while maintaining the pressure in the reactor at0.15 MPa (gauge pressure) and the temperature at 40° C., the abovebenzene solution (6 ml) was injected and stirred for 0.3 hour. Further,while maintaining the temperature in the reactor at 40° C., the abovebenzene solution (6 ml) was injected and stirred for 1.1 hours, andnitrogen gas was supplied for 1.0 hour. The ¹⁹F-NMR yield of theabove-identified compound contained in the product was 94%.

¹⁹F-NMR(376.0 MHz, solvent CDCl₃, standard: CFCl₃) δ (ppm): −83.4 (6F),−88.8(4F), −92.2(4F), −122.2(4F).

Example 4-3 Preparation Example for FCOCF₂OCF₂COF by Dissociation of anEster Bond in a Liquid Phase

CF₃CF₂COO(CF₂)₂O(CF₂)₂OCOCF₂CF₃ (6.0 g) obtained in Example 4-2 wascharged together with NaF (0.09 g) powder into a flask and heated at100° C. for 5 hours in an oil bath, while vigorously stirring. At theupper portion of the flask, a reflux condenser adjusted to a temperatureof 20° C. and a gas-collecting fluororesin container were installed inseries. After cooling, 0.5 g of a liquid sample and 5.4 g of a gaseoussample were recovered. As a result of the analysis by GC-MS, it wasconfirmed that the gaseous sample contained CF₃CF₂COF and theabove-identified compound as the main products. The yield of theabove-identified compound was obtained and found to be 85.6%.

Example 5 Example 5-1 Preparation Example forHO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCH₂Ph

HO(CH₂)₂O(CH₂)₂OH (21.2 g), potassium hydroxide (11.2 g) and dioxane(100 ml) were charged into a four necked flask and heated to an internaltemperature of 63° C. to dissolve potassium hydroxide. A solutionobtained by dissolving 32.0 g of TsOCH(CH₃)CH₂OCH₂Ph obtained in Example2-1 in dioxane (50 ml), was dropwise added over a period of 30 minutes,and while maintaining the internal temperature within a range of from 60to 100° C., stirring was continued for 13.5 hours. The mixture was leftto cool, then added to water (200 ml) and extracted three times withdichloromethane (50 ml). The organic layer was washed with water (20ml). It was dried over magnesium sulfate, filtered and then concentratedby an evaporator to obtain a crude product (52 g). it was purified bysilica gel chromatography to obtain 9.32 g of the above-identifiedcompound.

¹H-NMR(300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.17(d, J=6.3Hz, 3H), 2.8 (bs, 1H), 3.40-−3.52(m, 2H), 3.58-3.73(m, 7H), 4.54(m, 2H),7.26-7.34(m, 5H).

Example 5-2: Preparation Example for HO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OH

Interior of a round bottom flask was flushed with argon, and 5%palladium-carbon powder (0.9 g) was charged. Ethanol (50 ml) andHO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCH₂Ph (9.21 g) obtained in Example 5-1 wereadded, then deaerated and flushed with hydrogen. The mixture was stirredat room temperature for 17 hours and then filtered through cerite. Thefiltrate was concentrated by an evaporator to obtain 5.45 g of theabove-identified compound.

¹H-NMR (300.4 MHz, solvent: CDCl₃, solvent: TMS) δ (ppm): 1.13(d, J=6.2Hz, 3H), 3.20-3.82(m, 11H).

Example 5-3 Preparation Example forCF₃CF₂COO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCOCF₂CF₃

HO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OH (5.1 g) obtained in Example 5-2 andchloroform (10 g) were charged into a flask and stirred whilemaintaining the internal temperature at 30° C. Together with nitrogen,CF₃CF₂COF (191 g) was supplied while maintaining the internaltemperature at 30° C. After completion of the reaction, while supplyingnitrogen gas, stirring was continued at an internal temperature of 30°C. for 2 hours, and then, a 5% NaHCO₃ aqueous solution (30 ml) was addedat an internal temperature of at most 15° C.

The obtained crude liquid was subjected to liquid separation andpurified by silica gel column chromatography (developing solvent: R-225)to obtain the above-identified compound (5.0 g). The GC purity was 99%.

¹H-NMR(300.4 MHz, solvent: CDCl₃, standard: TMS) δ (ppm): 1.21(d, J=6.6Hz, 3H), 3.58˜3.81(m, 7H), 4.33(d, J=5.4 Hz, 2H), 4.50˜4.53(m, 2H).

¹⁹F-NMR (282.7 MHz, solvent: CDCl₃, standard: CFCl₃) δ (ppm):−82.96(3F), −82.99(3F), −121.46(2F), −121.53(2F).

Example 5-4 Preparation Example forCF₃CF₂COO(CF₂)₂O(CF₂)₂OCF(CF₃)CF₂OCOCF₂CF₃

In the same autoclave as in Example 2-5, R-113 (312 g) was added, andpreparation was made under the same conditions except that 20% fluorinegas was supplied at a flow rate of 12.72 /hr for 1 hour.

Then, while supplying 20% fluorine gas at the same flow rate, a solutionhaving CF₃CF₂COO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCOCF₂CF₃ (5.0 g) obtained inExample 5-3 dissolved in R-113 (100 g), was injected over a period of3.9 hours.

Then, while supplying 20% fluorine gas at the same flow rate andmaintaining the pressure of the reactor at 0.15 MPa (gauge pressure),the temperature was raised from 25° C. to 40° C., and at the same time,a R-113 solution (9 ml) containing 0.01 g/ml of benzene, was injected.The benzene injection inlet of the autoclave was closed, and stirringwas continued for 0.3 hour. Then, while maintaining the pressure of thereactor at 0.15 MPa (gauge pressure) and the temperature at 40° C., theabove benzene solution (6 ml) was injected, and stirring was continuedfor 0.3 hour. Further, the operation of injecting the benzene solution(6 ml) and stirring for 0.3 hour, was repeated four times under the sameconditions, whereupon stirring was carried out for 0.7 hour. Further,nitrogen gas was supplied for 1.0 hour. The ¹⁹F-NMR yield of theabove-identified compound contained in the product, was 89%.

¹⁹F-NMR (376.0 MHz, solvent CDCl₃, standard: CFCl₃) δ (ppm): −80.5(3F),−83.4(6F), −85.9˜−87.5(4F), −89.0(4F), −92.3(2F), −122.3(4F),−145.6(1F).

Example 5—5 Preparation Example for FCOCF₂O(CF₂)₂OCF(CF₃)COF

CF₃CF₂COO(CF₂)₂O(CF₂)₂OCF(CF₃)CF₂OCOCF₂CF₃ (5.1 g) obtained in Example5-4 was charged together with 0.09 g of KF powder into a flask andheated at 40° C. for 2 hours in an oil bath while vigorously stirring.At an upper portion of the flask, a reflux condenser adjusted to atemperature of 20° C. and a gas-collecting fluororesin container wereinstalled in series. After cooling, a liquid sample (3.2 g) and agaseous sample (1.6 g) were recovered. By GC-MS, it was confirmed thatthe gaseous sample contained CF₃CF₂COF as the main product, and theliquid sample contained the above-identified compound as the mainproduct. Further, the ¹⁹F-NMR yield of the above-identified compoundcontained in the product was 92%.

¹⁹F-NMR (376.0 MHz, solvent CDCl₃, standard: CFCl₃) δ (ppm): 26.7(1F),14.6(1F), −77.2(2F), −82.0(3F), −84.2(1F), −88.2(2F), −91.3(1F),−131.0(1F).

Example 6 Preparation Example for FCO(CF₂)₂COF

Into a 3000 ml autoclave made of nickel, R-113 (2767 g) was added,stirred and maintained at 25° C. At the gas outlet of the autoclave, acooler maintained at 20° C., a packed layer of NaF pellets and a coolermaintained at −10° C. were installed in series. Further, a liquidreturning line was installed in order to return a liquid condensed fromthe cooler maintained at −10° C. to the autoclave. After supplyingnitrogen gas for 2.3 hours, fluorine gas diluted to 50% with nitrogengas (hereinafter referred to as 50% fluorine gas) was supplied at a flowrate of 7.79 /hr for 3 hours. Then, while supplying 50% fluorine gas atthe same flow rate, as the first fluorination, a R-113 (250.2 g)solution of CF₃CF₂COO(CH₂)₄OCOCF₂CF₃ (25.0 g) obtained in Example 1—1,was injected over a period of 6.0 hours, and the reaction crude liquid(241.1 g, ¹⁹F-NMR yield: 51%) was withdrawn. Second fluorination wascarried out in the same manner as the first fluorination, and thereaction crude liquid (241.0 g, ¹⁹F-NMR yield: 83%) was withdrawn. Then,third fluorination was carried out in the same manner as the firstfluorination, and the reaction crude liquid (240.9 g, ¹⁹F-NMR yield:89%) was withdrawn. Further, nitrogen gas was supplied for 1.8 hours,and the reaction crude liquid (2804.4 g, ¹⁹F-NMR yield of theabove-identified compound: 86%) was withdrawn.

Using the obtained above-identified compound, the reaction was carriedout in the same manner as in Example 1-3 to obtain FCO(CF₂)₂COF.

INDUSTRIAL APPLICABILITY

According to the method of the present invention, a compound useful as araw material for the production of various fluororesins can be obtainedin high yield in a short process by using an inexpensivereadily-available starting material. Further, according to the presentinvention, a novel compound useful as the raw material for producingfluororesins will be provided. The method of the present invention is amethod excellent in general applicability, which can be applied to theproduction of various compounds by using a starting material which isreadily available. And, by applying the method of the present invention,it is possible to produce known compounds economically advantageously,and it is possible to provide various novel fluorine-containingcompounds.

The entire disclosures of Japanese Patent Application No. 2000-210184filed on Jul. 11, 2000, Japanese Patent Application No. 2000-294994filed on Sep. 27, 2000 and Japanese Patent Application No. 2001-07560filed on Apr. 5, 2001 including specifications, claims and summaries areincorporated herein by reference in their entireties.

1. A compound selected from the compounds of the following formulae:CF₃CF₂COO(CH₂)₄OCOCF₂CF₃  (3-12),CF₃CF₂COOCH₂CH (CH₃)O(CH₂)₄OCOCF₂CF₃  (3-13),CF₃CF₂COO(CH₂)₂O(CH₂)₂OCOCF₂CF₃  (3-14),CF₃CF₂CF₂OCF(CF₃)COOCH₂CH(CH₃)O(CH₂)₅OCOCF(CF₃)—OCF₂CF₂CF₃  (3-15)CF₃CF₂COO(CH₂)₂O(CH₂)₂OCH(CH₃)CH₂OCOCF₂CF₃  (3-16),CF₃CF₂COOCF₂CF₂CF₂CF₂OCOCF₂CF₃  (4-12),  CF₃CF₂COOCF₂CF (CF₃)OCF₂CF₂CF₂CF₂COCF₂CF₃  (4-13),CF₃CF₂COOCF₂CF₂OCF₂CF₂OCOCF₂CF₃  (4-14),CF₃CF₂CF₂OCF(CF₃)COOCF₂CF(CF₃)OCF₂(CF₂)₃—CF₂OCOCF(CF₃)OCF₂CF₂CF₃  (4-15),CF₃CF₂COO(CF₂)₂O(CF₂)₂OCF(CF₃)CF₂OCOCF₂CF₃  (4-16),andFCOCF₂O(CF₂)₂OCF(CF₃)COF  (5-16).
 2. The compound according to claim 1which is compound (3-12).
 3. The compound according to claim 1 which iscompound (3-13).
 4. The compound according to claim 1 which is compound(3-14).
 5. The compound according to claim 1 which is compound (4-14).6. The compound according to claim 1 which is compound (5-16).